Skip to Main Content
IPv6 Essentials
book

IPv6 Essentials

by Silvia Hagen
July 2002
Beginner content levelBeginner
360 pages
11h 19m
English
O'Reilly Media, Inc.
Content preview from IPv6 Essentials

Telnet

Telnet is a virtual terminal protocol used to log into a computer across the Internet or an intranet. RFC 854 contains the Telnet protocol specification and RFC 855 contains the Telnet options specification. Telnet connects to a remote host by establishing a TCP connection over port 23 and passing keystrokes from the user’s keyboard to the remote machine as if they had been entered on a keyboard attached to the remote host. The Telnet protocol uses TCP for transport. No modifications have to be made to Telnet.

I had a Telnet server running on Windows 2000, accessing it from the Linux host Ford, and also did the opposite—running an IPv6-enabled Telnet server on the Linux host and accessing it with the Microsoft Telnet client. Both ways are no problem. The Telnet protocol works over TCP over IPv6 with the standard Telnet port number 23. Figure 9-7 shows the Telnet session.

A Telnet session over IPv6

Figure 9-7. A Telnet session over IPv6

The figure shows the negotiation of the Telnet session. In the detail window, you can see the layers: the MAC layer with Ethertype 86DD, the IPv6 layer using TCP value 6 in the Next Header field, the TCP layer using port 23 for Telnet, and the Telnet header. Telnet also sends passwords and all session data in clear text that an intermediary may discover. Software like SSH provides an encrypted terminal for security. SSH is IPv6-ready today and available on many platforms. ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

IPv6 Essentials, 2nd Edition

IPv6 Essentials, 2nd Edition

Silvia Hagen
IPv6 Security

IPv6 Security

Scott Hogg, Eric Vyncke

Publisher Resources

ISBN: 0596001258Catalog PageErrata